Ground compaction is required in many different situations. In many cases, compaction of horizontal surfaces is often required at the bottoms of trenches or excavations. Many different kinds of equipment have been developed for ground compaction, including a variety of compacting devices of the type which are supported on tractor tool-support booms and have a cylindrical compacting surface for application to the ground.
Examples of prior devices of this general type include those disclosed in the following U.S. Pat. Nos. 4,100,688 (Grist), 4,278,368 (Livesay), 3,595,411 (Ables), 3,891,342 (Roe) and 3,989,404 (Burton).
Many such devices of the prior art have significant problems and disadvantages, including some which are apparent in certain very common compaction tasks.
One principal problem is that compaction operations cannot be carried out by such prior devices along certain edges of the horizontal surfaces of a trench or excavation bottom, or whenever a vertical obstacle is immediately adjacent to the edge area to be compacted. For example, when the backhoe or other tool-carrying device is facing the trench wall or excavation wall, the cylindrical compacting surface usually cannot be applied, or applied effectively, to the edge of the horizontal surface--next to such wall. Compaction along an edge may be possible when the approach is made along the edge rather than toward it, but certain equipment of the prior art is inadequate when the edge is approached at an angle across the edge.
Edge compaction, at least even edge compaction, is difficult with certain prior equipment even when there is no vertical obstacle along the edge. And, such prior compaction equipment is also frequently inadequate for compaction at the bottoms of small excavations or holes.
Many such prior compaction devices are also extremely complex in structure and operation. In some cases, when not in use, they may interfere with normal backhoe bucket operations. Furthermore, due to their complexity they are often expensive.
It can be seen that prior backhoe-mounted cylindrical compaction tools have significant problems. There clearly is a need for an improved compacting apparatus of the type on a tractor tool-support boom.